@Keroro Do not take into account future expansions that would suddenly make miracles. Either you find the game is interesting enough to mod right now, even without G&K, either you do not. G&K did not change a lot of things anyway and, for 99% of mods, including some big ones, updating for G&K was pretty simple and fast (but the other 1%, including some very interesting mods, are now totally broken, which is a shame). Regarding the current state of civ5 modding. * We do not have access to the dll source code. This is bad because you need to guess a lot of things. This is bad also because you cannot create your own dll for your total conversion mod (but that would make it incompatible with many other mods). However there are plenty of things you can do with LUA alone, including some gameplay changes. * Lua and the UI is not that bad. It's lacking for sure, the API and UI have not been designed with modding in mind but, well, most of the time you miraculously manage to make your way out. Regarding LUA, well, if you like weakly typed dynamic languages, it's a pretty good one aside of its rotten "noobs-friendly" syntax ("if then"? Seriously?), its average and small API and its annoying error handling mechanics. * Art seems like the main problem: changing improvements seems painful or not totally possible, new leaders 3D art is not possible, units creation seems more complex, etc. This is true for all recent games actually: modern animation, models and texturing systems are more sophisticated, they are often created through proprietary third-party and expensive tools, etc. Better graphics are bad for modding and the same thing happened when games moved from 2D to 3D, we will see whether things again return to a more manageable state for modders. * Expect many crashes and such. Civ was already easily crashing for apparently no reason (failed assertions nowhere reported I guess), G&K made it worse with new bugs and crashes that will annoy you and your users. @binthuy71 And I agree with PawelS: some of us perfectly know how to handle C++ once the DLL source code is released.